1. Field of the Invention
This invention relates to supplementary construction to be placed on an existing building for the purpose of selectively creating air flow over external roof and/or wall surfaces or a body of trapped air over such external surfaces wherein the former serves to cool the building structure and the latter serves to heat the building structure. The subject supplementary construction is specifically designed to take advantage of natural occurring phenomenon including the continued flow of air currents through convection, the sun's radiant energy and naturally forced air or wind.
2. Description of the Prior Art
The prior art has long recognized that the proper ventilation of building structures is necessary and highly desirable in order to achieve certain cooling effects within the building as well as prevent damage to the roof and adjacent building structure from condensation. With regard to the latter, adequate ventilation is important for cooling but also particularly important where the roof is insulated. This is due to the effect that inadequate or no ventilation in an insulated roof structure permits the formation of condensation which, in addition to damaging the roof and the interior finishes, reduces the effectiveness of such insulation.
Prior art structures and techniques directed to ventilating building structures are disclosed and generally represented in the following patents to Gilman, U.S. Pat. No. 340,570; Katt et al, U.S. Pat. No. 2,954,727; Meyer et al, U.S. Pat. No. 3,236,170; and Belden, U.S. Pat. No. 3,481,263.
While the invention disclosed in the aforementioned patents are operable for their specifically intended function they are of questionable aid when it is desirable to effect cooling or heating of a building structure through utilizing the technique of cooling or heating external wall or roof surfaces by incorporating naturally occurring phenomenon.